Add a \ in front of open-paren-in-column-0 in docstrings. Otherwise
indentation and font-lock get confused.
(idlwave-function-menu): Use defalias so the funs are called interactively.
Don't rely on knowledge about which Emacs provides imenu or func-menu.
(idlwave-calculate-cont-indent): Fix typo.
(idlwave-font-lock-keywords-*): Don't use setq on a defconst.
Remove unused variables.